Imaging Features of Neonatal Bowel Obstruction

Radiologic evaluation of neonatal bowel obstruction is challenging owing to the overlapping clinical features and imaging appearances of the most common differential diagnoses. The key to providing an appropriate differential diagnosis comes from a combination of the patient's gestational age, clinical features, and imaging findings. While assessment of radiographs can confirm bowel obstruction and indicate whether it is likely proximal or distal, additional findings at upper or lower gastrointestinal contrast study together with use of US are important in providing an appropriate differential diagnosis. The authors provide an in-depth assessment of the appearances of the most common differential diagnoses of proximal and distal neonatal bowel obstruction at abdominal radiography and upper and lower gastrointestinal contrast studies. These are divided into imaging patterns and their associated differential diagnoses on the basis of abdominal radiographic findings. These findings include esophageal atresia variants including the "single bubble," "double bubble," and "triple bubble" and distal bowel obstruction involving the small and large bowel. Entities discussed include esophageal atresia, hypertrophic pyloric stenosis, pyloric atresia, duodenal atresia, duodenal web, malrotation with midgut volvulus, jejunal atresia, ileal atresia, meconium ileus, segmental volvulus, internal hernia, colonic atresia, Hirschsprung disease, and functional immaturity of the large bowel. The authors include the advantages of abdominal US in this algorithm, particularly for hypertrophic pyloric stenosis, duodenal web, malrotation with midgut volvulus, and segmental volvulus. ©RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

The prevalence and clinical presentation of Hirschsprung's disease in preterm infants: a systematic review and meta-analysis

PURPOSE

Hirschsprung's disease (HD) is a rare occurrence in premature infants, and the exact prevalence varying across studies. Thus, we conducted this study to determine the prevalence of and clinical presentation of HD in preterm infants.

METHODS

The PubMed, EmBase, and Cochrane library databases were searched for eligible studies throughout May 2021. The pooled incidence with 95% confidence interval (CI) was calculated using the random-effects model.

RESULTS

Thirty studies involved 4,557 children with HD were included. The pooled proportion of HD patients who were preterm infants was 7% (95% CI 5-8%; P < 0.001); the sensitivity analysis indicated that the pooled prevalence of preterm infants with HD ranged from 5.0% to 5.6%. Moreover, the pooled incidence of abdominal distention in HD patients was 83% (P < 0.001), that of vomiting was 61% (P < 0.001), that of bilious vomiting was 54% (P < 0.001), that of delayed meconium passage was 48% (P < 0.001), that of constipation was 44% (P < 0.001), and that of enterocolitis was 13% (P < 0.001).

CONCLUSIONS

This study reported the prevalence of HD patients who were preterm infants, and the most common presentations were abdominal distention, vomiting, bilious vomiting, delayed meconium passage, constipation, and enterocolitis.

Prospective study reveals a microbiome signature that predicts the occurrence of post-operative enterocolitis in Hirschsprung disease (HSCR) patients

Hirschsprung disease (HSCR) is a birth defect with an approximate incidence of 1/5,000 live births, and up to one-third of HSCR patients develop Hirschsprung-associated enterocolitis (HAEC), the leading cause of HSCR-related death. Very little is known about the pathogenesis, prevention, and early diagnosis of HAEC. Here, we used a prospective study to investigate the enteric microbiome composition at the time of surgery as a predictor for developing postoperative HAEC. We identified a microbiome signature containing 21 operational taxonomic units (OTUs) that can potentially predict postoperative HAEC with ~85% accuracy. Furthermore, we identified exclusive breastfeeding as a novel protective factor for total HAEC (i.e., preoperative and postoperative HAEC combined). In addition, we discovered that breastfeeding was associated with a lowered risk for HAEC potentially mediated by modulating the gut microbiome composition characterized by a lower abundance of Gram-negative bacteria and lower LPS concentrations. In conclusion, modulating the gut microbiome by encouraging breastfeeding might prevent HAEC progression in HSCR patients.

Suction Rectal Biopsy is Accurate in Late Preterm Infants with Suspected Hirschsprung Disease

BACKGROUND

Few data are available to substantiate the dogma commonly held by pediatric surgeons and pediatric pathologists that rectal biopsies may be inaccurate or risky in preterm neonates. We aimed to address these concerns.

METHODS

We performed a single-institution retrospective review of patients who underwent suction rectal biopsies at <37 weeks corrected age from 2009 to 2018. The primary outcomes were accuracy of biopsy results and procedural complications.

RESULTS

Forty-nine patients underwent suction rectal biopsy at <37 weeks corrected age. Mean gestational age at biopsy was 35.2 weeks (range 32.1-36.9) and mean weight was 2126 g (range 1590-3100). Five (10%) infants had biopsies positive for Hirschsprung Disease. All 5 later underwent pull-through operations and had pathologic confirmation of an aganglionic segment. The remaining 44 (90%) had biopsies showing ganglion cells. None were later found to have HD during the follow up period. Those who underwent biopsy at <2000 g (16/44) had 100% sensitivity [95% CI 48, 100] and specificity [95% CI 92, 100] (2 true positives, 14 true negatives). There were no complications identified.

CONCLUSION

Suction rectal biopsy can be performed safely in preterm infants as small as 1590-2000 g with high accuracy. Clinicians should not hesitate to perform a biopsy for a premature infant when clinically appropriate.

TYPE OF STUDY

Study of a diagnostic test.

LEVEL OF EVIDENCE

Level IV.

Epidemiological characteristics of Hirschsprung's disease (HSCR): Results of a case series of fifty patients from Bangladesh

BACKGROUND

The epidemiology of Hirschsprung's disease (HSCR) in Bangladesh has never been studied. The aim of this study was to determine the epidemiological characteristics of HSCR in Bangladesh.

METHODS

Data from fifty patients were collected prospectively from two hospitals in Chittagong, Bangladesh.

RESULTS

The rate of consanguinity (16%) among parents of HSCR patients was higher than that of the general population (10%). Maternal age at the time of birth of the affected child was ≤30years in all cases except one. No association was found between parents' occupation and HSCR. No patient was born preterm and only three patients (6%) had low birth weight. Nine patients (18%) had associated anomalies. We found coexistence of bilateral accessory tragi and ankyloglossia in one patient, and coexistence of rectal duplication cyst in another. Neither anomaly had been previously reported in HSCR patients.

CONCLUSIONS

Our study suggests that consanguinity might increase the risk of HSCR whereas advanced maternal age does not. HSCR patients were found more likely to born at term and with normal birth weight. The coexistence of HSCR with previously unreported anomalies highlights the diversity of conditions that can co-occur with HSCR.

LEVELS OF EVIDENCE

IV.

Hirschsprung's disease in the UK and Ireland: incidence and anomalies

OBJECTIVES

To describe clinical characteristics and preoperative management of a national cohort of infants with Hirschsprung's disease (HD).

DESIGN

Population-based cohort study of all live-born infants with HD born in the UK and Ireland from October 2010 to September 2012.

SETTING

All 28 paediatric surgical centres in the UK and Ireland.

PARTICIPANTS

305 infants presenting before 6 months of age with histologically proven HD.

MAIN OUTCOME MEASURES

Incidence, clinical characteristics including gestational age, birth weight, gender, associated anomalies; age and clinical features at presentation; and use of rectal washouts or stoma.

RESULTS

The incidence of HD in the UK and Ireland was 1.8 per 10 000 live births (95% CI 1.5 to 1.9). Male to female ratio was 3.3:1. An associated anomaly was identified in 23% (69), with 15% (47) having a recognisable syndrome. The proportion of infants who presented and were diagnosed in the neonatal period was 91.5% (279) and 83.9% (256), respectively. 23.9% (73) and 44.2% (135) passed meconium within 24 and 48 hours of birth. 81% (246) first presented to a hospital without tertiary paediatric surgical services, necessitating interhospital transfer. Initial colonic decompression was by rectal washouts in 86.2% (263) and by defunctioning stoma in 12.8% (39). Subsequently, 27.4% (72) of infants failed management with rectal washouts and required a delayed stoma, resulting in 36.4% (111) of infants having a stoma.

CONCLUSIONS

In this population-based cohort, presentation outside the neonatal period was rare. Nearly half of the infants with HD passed meconium within 48 hours of birth and over one third were managed with a stoma.

Genetic impact on the treatment & management of Hirschsprung disease

BACKGROUND

The identification of Hirschsprung's disease (HD) as a genetic condition has been a major step forward in understanding the development of the enteric nervous system and conditions arising from ganglion cell maldevelopment.

METHOD

A study of the role of genetics in HD was carried out based on previously published findings from more than 400 cases of HD.

RESULTS

There are at least 7 pertinent clinical questions related to HD which were further investigated. These included: diagnosis, familial recurrence, long segment and total colonic aganglionosis, syndromic associations, the question of HD-associated enterocolitis, potential causes of postoperative obstructive symptoms after successful surgery, and the apparent low prevalence in premature infants. This review aimed at evaluating the most important concepts of where we have got to in our understanding of where genetic solutions/directions to these clinical problems might lie. Possible genetic reasons for the low prevalence in premature infants was also considered and the possible plasticity of the ENS at that stage as a potential "door of hope" in the future management of HD.

CONCLUSION

The study of genetics has made a massive contribution to the understanding and management of HD. It opens a "door of hope" to the future management of the condition.

LEVEL OF EVIDENCE

Level V.

Established and Emerging Concepts in Hirschsprung’s-Associated Enterocolitis

Hirschsprung's disease (HSCR) is a common cause of neonatal bowel obstruction and the approach to diagnosis and surgical treatment is well defined and accepted. Hirschsprung's-associated enterocolitis (HAEC) remains a frequent cause of pre-operative and post-operative morbidity and mortality, with unchanged treatment guidelines over multiple decades. Recent advances in our understanding of the genetics underlying HSCR have allowed the development of animal models, some of which recapitulate the HAEC phenotype. These animal models, along with recent translational studies, have implicated multiple facets of mucosal immunity and microbiome dysbiosis in the development of HAEC. Here, we will review the established epidemiology, modes of diagnosis and treatment of HAEC. Furthermore, we will explore emerging concepts in the pathogenesis of this disease; including animal models, alterations in mucosal immunity, dysbiosis of the intestinal microbiome, specific genetic susceptibility, and novel treatment modalities.

Syndromic Hirschsprung's disease and associated congenital heart disease: a systematic review

PURPOSE

Hirschsprung's disease (HD) occurs as an isolated phenotype in 70% of infants and is associated with additional congenital anomalies or syndromes in approximately 30% of patients. The cardiac development depends on neural crest cell proliferation and is closely related to the formation of the enteric nervous system. HD associated with congenital heart disease (CHD) has been reported in 5-8% of cases, with septation defects being the most frequently recorded abnormalities. However, the prevalence of HD associated with CHD in infants with syndromic disorders is not well documented. This systematic review was designed to determine the prevalence of CHD in syndromic HD.

METHODS

A systematic review of the literature using the keywords "Hirschsprung's disease", "aganglionosis", "congenital megacolon", "congenital heart disease" and "congenital heart defect" was performed. Resulting publications were reviewed for epidemiology and morbidity. Reference lists were screened for additional relevant studies.

RESULTS

A total of fifty-two publications from 1963 to 2014 reported data on infants with HD associated with CHD. The overall reported prevalence of HD associated with CHD in infants without chromosomal disorders was 3%. In infants with syndromic disorders, the overall prevalence of HD associated with CHD ranged from 20 to 80 % (overall prevalence 51%). Septation defects were recorded in 57% (atrial septal defects in 29%, ventricular septal defects in 32%), a patent ductus arteriosus in 39%, vascular abnormalities in 16%, valvular heart defects in 4% and Tetralogy of Fallot in 7%.

CONCLUSION

The prevalence of HD associated with CHD is much higher in infants with chromosomal disorders compared to infants without associated syndromes. A routine echocardiogram should be performed in all infants with syndromic HD to exclude cardiac abnormalities.

Prevalence of Hirschsprung's disease in premature infants: a systematic review

PURPOSE

Intestinal dysmotility in preterm infants has often been attributed to immature enteric nervous system. It is frequently reported that Hirschsprung's disease (HD) is rare in premature infants. The exact prevalence of HD in premature infants is not well documented. The classical signs of HD may often not be identified due to the complexity of symptoms of prematurity itself. This systematic review was designed to determine the prevalence and presentation of HD in premature infants.

METHODS

A systematic review of the literature using the keywords "Hirschsprung's disease", "aganglionosis", "congenital megacolon", "premature" and "preterm" was performed. Resulting publications were reviewed for epidemiology and morbidity. Only infants born <37 weeks of gestation or described as preterm birth by the authors were included. Reference lists were screened for additional relevant studies.

RESULTS

Twenty-six publications from 1964 to 2013 reported data on premature infants with HD. Out of a total number of 4,147 infants, prematurity was recorded in 257 cases, giving a prevalence rate of 6 % of preterm infants diagnosed with HD. During 1964-1999, reported prevalence of HD in premature infants ranged from 1.7 to 9.2 % (overall prevalence 5 %) and during 2000-2013 prevalence ranged from 4 to 19.4 % (overall prevalence 14 %). The prevalence of total colonic aganglionosis in premature infants was 13 % (15 out of 118 infants). Mean gestational age of preterm infants was 34.5 (± 0.7) weeks and mean age at diagnosis ranged from 18.3 days to 3.9 months. Abdominal distension was observed in 80 % of preterm infants, delayed passage of meconium in 57 and 37 % of premature infants presented with bile-stained vomiting.

CONCLUSION

In recent years, higher prevalence of HD has been reported in premature infants compared to previous years. Hirschsprung's disease should be considered in preterm infants presenting with features of intestinal obstruction.